Banana Upside-Down Cake with Malted Pudding

Ingredients

• For banana cake:
• 2/3 cup light brown sugar
• 2 1/2 sticks butter, softened, divided
• 3 firm, ripe whole bananas, halved lengthwise, plus 1 cup mashed ripe bananas
• 2/3 cup sugar
• 3 eggs, separated
• 2 cups all-purpose flour
• 1 teaspoon baking powder
• 1/2 teaspoon baking soda
• 1/2 teaspoon salt
• 1/2 cup buttermilk, shaken
• 1 teaspoon vanilla extract
• Brown Butter Walnut Buttercream
• 1 1/2 sticks plus 3 tablespoons butter
• 1/3 cup walnuts, chopped
• 1 teaspoon kosher salt
• 6 egg whites
• For assembly:
• 1 cup My Bro's Malted Milk Pudding
• Simple syrup or melted apricot jam, optional
• My Bro's Malted Milk Pudding
• 1 1/4 cups whole milk
• 1 1/4 cups heavy cream
• 1/2 cup sugar
• 3 tablespoons cornstarch
• 3 egg yolks
• 1 cup plus 2 tablespoons malted milk powder
• 1 ounce bittersweet chocolate, finely chopped

Directions

1. First, make the pudding. In a medium saucepan, whisk all of the pudding ingredients except the vanilla with some real energy. Set the pan over medium-high heat and cook, whisking the whole time, until the pudding thickens, 6-7 minutes. You’ll know it is ready when the whisk leaves a faint trail as you lift it. Whisk in the vanilla. Pour the pudding through a fine-mesh sieve into a bowl, using a spatula to help it through. Let it stand at room temperature for 10 minutes, then press plastic wrap directly onto the pudding and refrigerate until fully cold, 2 hours.
2. Make the cake. Heat the oven to 350F. Spray two 8-inch round cake pans with cooking spray and set them aside. In a small saucepan, stir together the brown sugar and 1 1/2 sticks butter. Bring the mixture to a boil and cook until the sugar has melted and the sauce looks smooth, 3-4 minutes. Carefully portion the hot sauce evenly into the cake pans. Lay 3 banana halves in each pan, cut side down, then move the pans to the freezer while you prepare the batter so the bananas stay put when the batter goes on top.
3. In the bowl of a stand mixer with the paddle attached, beat the remaining 1 stick butter with the sugar on high speed until pale, soft, and fluffy, 4-5 minutes. Add the mashed bananas and beat until mixed in, 30 seconds.
4. In a medium bowl, whisk the flour, baking powder, baking soda, and salt. Stop the mixer, add the dry mixture, then start again on low and gradually bring it up to medium, mixing until everything is evenly combined, 1 minute. Add the buttermilk and vanilla extract and mix for 1 minute more. Scrape the batter into a large bowl and set it aside, then wash the mixer bowl well and dry it completely.
5. Attach the whisk to the mixer, add the reserved egg whites, and beat on high until soft peaks form, 1-2 minutes. With a spatula, mix a small scoop of the whites into the banana batter to lighten it. Fold in the rest of the egg whites gently, taking care not to knock the air out of the batter.
6. Divide the batter between the prepared pans. Bake until a cake tester or wooden toothpick poked into the middle comes out clean, 30-35 minutes. Take the cakes out of the oven and leave them in the pans for 10 minutes, then invert them onto a cooling rack and cool to room temperature with the banana sides facing up, 30 minutes.
7. Make the frosting. Heat the oven to 350F. In a small saucepan, cook 3 tablespoons of butter over medium-high heat until it smells nutty and brown specks appear, 2-3 minutes. Add the walnuts and salt, toss to coat, and spread the mixture on a parchment-lined rimmed baking sheet.
8. Toast the walnuts until they smell fragrant and look lightly browned, 5-7 minutes. Let them cool at room temperature until they are comfortable to handle, then either pulse them finely in a food processor or chop them very finely by hand.
9. Place the stand mixer bowl over a saucepan of simmering water and whisk the egg whites and sugar until the mixture feels warm to the touch. Move the bowl back to the stand mixer fitted with the whip attachment and beat on high until the meringue is stiff, shiny, and cool, 4-5 minutes. Add the remaining butter 1 tablespoon at a time, whipping until the frosting becomes fluffy, 4-5 minutes. Add the chopped walnut mixture and mix until combined, 1-2 minutes.
10. Assemble the cake. Set 1 cake layer on a lazy Susan or a large, flat place, banana side up, using the less polished layer for the bottom. Pipe a buttercream border around the top about 1/4 inch in from the edge to make a dam. Spoon the malted pudding into the center and level it with a spatula or knife.
11. Carefully set the second, prettier banana cake layer on top, banana side up, and press lightly to even the cake, nudging the buttercream close to the edges. Add more buttercream where needed so the sides are flush with the edge of the laters, then use an offset spatula to smooth the sides into a crumb coat, leaving the top uncovered. Refrigerate until the buttercream is firm, 30 minutes.
12. Use the remaining frosting on the sides of the cake only, leaving the top bare so the caramelized bananas show. If you want to gloss the bananas a bit, brush the top with a little simple syrup or melted apricot jam.